Design of a Cell Phone Lens-Based Miniature Microscope with Configurable Magnification Ratio

Application of cell-phone-based microscopes has been hindered by limitations such as inferior image quality, fixed magnification and inconvenient operation. In this paper, we propose a reverse cell phone lens-based miniature microscope with a configurable magnification ratio. By switching the objectives of three camera lens and applying the digital zooming function of the cell phone, a cell phone microscope is built with the continuously configurable magnification ratio between 0.8×–11.5×. At the same time, the miniature microscope can capture high-quality microscopic images with a maximum resolution of up to 575 lp/mm and a maximum field of view (FOV) of up to 7213 × 5443 um. Furthermore, by moving the tube lens module of the microscope out of the cell phone body, the built miniature microscope is as compact as a <20 mm side length cube, improving operational experience profoundly. The proposed scheme marks a big step forward in terms of the imaging performance and user operational convenience for cell phone microscopes.

A Clock Optimization Method in the Digital Zooming of the Image Signal Processing System

We address the problem of producing an enlarged picture from a given digital image (zooming). We propose a method that tries to take into account the difficulty to apply the very fast clock in the digital zooming unit of an ISP system. The ISP system hardware is realized in the FPGA and the zooming algorithm is parabola interpolation architecture. This paper presents an optimization method by using a synchronization FIFO to greatly reduce the clock frequency of the digital zooming unit, and by this the power consumption is also decreased significantly.